A NOTE ON SEALING PIEZOMETERS IN BOREHOLES

THE SITUATION IS EXAMINED IN WHICH A PIEZOMETER IS INSTALLED IN A BOREHOLE WHICH IS SEALED WITH A GROUT OF GREATER PERMEABILITY THAN THE SOIL SURROUNDING THE PIEZOMETER. AN APPROXIMATE RELATIONSHIP BETWEEN THE ERROR IN PIEZOMETER READING AND THE RELATIVE PERMEABILITIES OF THE GROUT AND GROUND IS ESTABLISHED FOR STEADY FLOW CONDITIONS. IT IS SHOWN THAT THE GROUT MUST HAVE A PERMEABILITY CONSIDERABLY HIGHER THAN THAT OF THE GROUND FOR THE PIEZOMETER READING TO HAVE A SIGNIFICANT ERROR. A SIMILAR RELATIONSHIP IS DERIVED FOR THE ERROR IN THE DETERMINATION OF PERMEABILITY FROM A CONSTANT HEAD PERMEABILITY TEST ON A BOREHOLE PIEZOMETER. IT IS SHOWN THAT THE PERMEABILITY OF THE SEALING GROUT MAY BE SIGNIFICANTLY GREATER THAN THE GROUND PERMEABILITY BEFORE A SIGNIFICANT ERROR RESULTS. IT IS SHOWN THAT IN CERTAIN CIRCUMSTANCES THE FILTER MATERIAL COMMONLY USED TO SURROUND THE PIEZOMETER TIP MAY BE OMITTED. THIS FACILITATES THE INSTALLATION OF A LARGE NUMBER OF PIEZOMETERS AT DIFFERENT LEVELS IN ONE SMALL DIAMETER BOREHOLE. AN INSTALLATION OF THIS TYPE AT THE BALDERHEAD DAM IS DESCRIBED. /RRL/A/

  • Availability:
  • Supplemental Notes:
    • Vol 19, No 3, PP 405-413, 9 FIG, 10 REF
  • Corporate Authors:

    Road Research Laboratory /UK

    ,    
  • Authors:
    • Vaughnan, P R
  • Publication Date: 0

Media Info

  • Serial:
    • GEOTECHNIQUE
    • Volume: 4
    • Issue Number: 3
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00229346
  • Record Type: Publication
  • Source Agency: Road Research Laboratory /UK
  • Files: TRIS
  • Created Date: May 13 1970 12:00AM